Thanks @joris.mak
I'm not a programmer but I can understand somethings about that. However, I do not know how to use 'mklink / j' or use GUI utilities.

I started to follow your second advise (for me easier to understand). I opened this file:
'Resources / app / js / mainjs / config.js' from Sia program, and in this file I can see some vars, one of these is:
Datadir: Path.join (app.getPath ('userData'), './sia'),
Its value is in "C: \ Users \ UserName \ AppData \ Roaming \ Sia-UI \ config.json"

If I change this value, when I start SIA appears an error.
The error apears with folder moved or not moved.
This error signs to this file: config.json (from 'resources / app / js / mainjs / config.js' Sia extrated program and other parameters).

I think the file with 'Path.join' value is the target, but I do not know which file could content it yet.
Thanks for your answer.